I have created a quadcopter with a 24” propeller and a 6 cell battery.
I completed the initial setup according to the documentation and was ready to fly it, but it crashed.
After arming, I throttled up to take off in AltHold mode, then throttled down slightly to adjust altitude, the aircraft instantly lost altitude and even though I throttled up, I could not avoid hitting the ground.
I checked the logs, but I could not discern what part of the adjustment was incorrect.
Please take a look at the log data and advise me.
Thank you in advance.
I’d also like to emphasize one very important thing: Make sure that you have a switch on your remote that quickly lets you switch between stabilize and loiter, and that you’re always aware of it.
Many tutorials tell you to perform the first flight of your uncalibrated drone in stabilize mode, completely ignoring how extremely hard this can be, especially for a beginner. The drone may show strong reaction even to the smallest input or wind force, which can quickly cause a pilot to lose control or even panic. I crashed many times this way and I still feel uncomfortable flying in stabilize mode, even on calibrated drones.
Even before your first calibration flight in stabilize mode, I’d recommend making your very first flights in loiter mode, and, when airborne, switch to stabilize, experiment a little, and quickly switch back to loiter if it gets uncomfortable.
@amilcarlucas or do you see a good reason against this? Maybe a potential problem I’m overlooking?
Unfortunately we should to build drone first, then study to fly on it…
Be noted- extremmely important to set “PILOT_THR_BHV= 1”
Otherwice possible situation when you can’t land drone in AltHold.
Please note that by “first flights”, I meant hovering in 1-2 metres, as described in the methodical guide. I should have mentioned that.
Anyway, I don’t understand the problem. The drone might be fighting to keep the position and act unstable, but won’t that be the same problem in stabilize mode, only that here nothing will help you keep the position?
I actually always did the first PID tuning in loiter mode. There, I can, in “relative” safety, observe the PID do it’s thing and work out a fair initial stabilize flight setup.
But why? What is the technical reason that an untuned loiter flight (with the constant option of switching to stabilize) is so much more dangerous that an untuned stabilize flight. Again, there might be a good reason I’m not aware of, but everybody tells you to start in stabilize mode the first time you lift off, and nobody ever tells you why.
BTW.: Sorry for hijacking the thread like this. I don’t think we’re still helping the OP here…
By all means, yes! When in doubt, he is clearly the more experienced pilot. I mainly work with autonomous drones and rarely get to fly one by hand these days.
However, I’m still not convinced. Control theory, as all theories, gives a general rule, assuming completely unknown loops of the worst possible complexity. The actual effects depend on the implementation, and even then, it comes down to a tradeoff of what is more dangerous: the danger of the added loop or the danger of “being that loop yourself”.
But I’ve stressed this thread enough, I might take it to it’s own thread one day.
you need to set the first mode is Stablelize and then Althold and then Poshold or something something !! and need to bring it in to the ground , dont try it in the rooptop or need to check your surface, its possible if your surface is flat and the GPS and Compass working good !